Re: RP Project-Die Cast parts

From: Charles Overy (
Date: Mon Aug 09 1999 - 08:39:08 EEST


Reading many of the replies on the list (great thread!) It seems to me that you
need to carefully define your terms. As you have chosen a part that has already
been designed and built you are eliminating the whole design process. If you
ignore the reduction in design cycle time and soft costs of error reduction etc.
from rapid concept builds then you will almost definitely ignore most of the
benefits of current RP machines. My take on the market is that most commercial
machines are sold to generate strategic advantage and soft cost reduction - these
costs are difficult to quantify which is my opinion on why the market for the
machines is slack despite keen interest - however the costs are real.
     So if you consider just the cost to manufacture will you consider amortizing
the machine costs, how will you deal with labor costs, tooling changes etc.? The
problems of accounting for these in a large shop like Caterpillar is very different
from a small shop.
Also when you consider just manufacturing you ignore the whole back end of the
product/part life cycle. The costs here are numerous and large including
inventorying and shipping of original parts, replacement part inventory, cost of
carrying inventory, inventory taxes, short run or redesign if necessary to
support premature failures and above planned replacements, inventory disposal (
which is often more than the value of the parts - especially if you work for the
government or government contractor!), parts distribution network including
associated escalating IT costs to track and manage etc. etc. etc.

Overall, I would argue that if you just look at the straight cost of goods and
direct charges (tooling, labor and machine time etc.) the result is a foregone
conclusion for a "standard" (whatever that means) part in volume. However if you
consider the entire life of the part and its relationship to the product and even
future products in the line - then the figures will change substantially.

Perhaps you can even convince some machine vendors that a large market exists
outside of the realm of "strategic advantage" (read price premium) and in the realm
of numbers that corporate controllers and yes, even small business people can
justify. If you really want to get people excited try going out of the mechanical
design shop with your friend at Caterpillar over to inventory or accounting - tell
them that the economic order quantity on just 5% of the parts in inventory is now 1
and lead time is 24 hours.

Good luck
P.S. Don't really take any of my suggestions - It will make your life hell -


Laser Graphic Manufacturing
Precision Models for Architecture and Development

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